What is "pvrtc"

PVRTC and PVRTC2 are a family of lossy, fixed-rate texture compression formats used in PowerVR's MBX (PVRTC only), SGX and Rogue technologies. The PVRTC algorithm is documented in Simon Fenney's paper "Texture Compression using Low-Frequency Signal Modulation" that was presented at Graphics Hardware 2003.

These differ from block-based texture formats such as S3TC and Ericsson Texture Compression (ETC) in that the compressed image is represented by two lower resolution images which are bilinearly upscaled and then blended according to low precision, per-pixel weights. They also differ in that they support ARGB data in both 4-bpp and 2-bpp modes.

PVRTC is the compressed texture format used in all generations of the iPhone, iPod Touch, and iPad. It is also supported in certain Android devices, that use PowerVR GPUs.